14 letters
- perfectiveness28
- perfidiousness23
- permissiveness25
- perniciousness23
- personableness23
- persuasiveness23
- portentousness20
- possessionless19
- possessiveness22
- posthumousness25
- precariousness22
- precociousness25
- predaceousness23
- pretensionless20
- preventiveness27
- prodigiousness22
- productiveness27
- profitableness25
- propitiousness22
- prosperousness22
- protectiveness25
- protrusiveness23
- pugnaciousness26
- purposefulness27
- rampageousness24
- reasonableness20
- rebelliousness21
- reflectiveness26
- refractiveness25
- refractoriness21
- regardlessness19
- regenerateness18
- regressiveness21
- relentlessness18
- remarkableness26
- remorsefulness23
- repetitiveness22
- repressiveness22
- resistlessness16
- respectfulness26
- respectiveness25
- responsiveness23
- revengefulness27
- ridiculousness22
- roadworthiness21
- robustiousness20
- roundaboutness22
- salubriousness21
- scandalousness22
- schoolmistress23
- scrupulousness25
- scurrilousness21
- seasonableness20
- shamefacedness27
- slanderousness19
- slatternliness18
- sobersidedness20
- softheadedness22
- solicitousness20
- speechlessness24
- spiritlessness19
- sprightfulness27
- stresslessness16
- stupendousness22
- subjectiveness35
- submissiveness26
- subversiveness27
- successfulness27
- successiveness26
- sufferableness26
- suggestiveness24
- superhumanness26
- supportiveness26
- surefootedness20
- susceptiveness26
- suspiciousness23
- systematicness23
- terminableness23
- thoughtfulness27
- threadbareness21
- thriftlessness21
- transitiveness20
- transitoriness16
- tremendousness21
- tumultuousness23
- tyrannicalness23
- ubiquitousness30
- umbrageousness25
- unaffectedness27
- unassumingness24
- unavailingness25
- unbecomingness29
- unchangingness28
- undeniableness23
- uneventfulness27
- unexpectedness31
- unfaithfulness27
- unfriendliness23
- unfruitfulness26
- ungraciousness23
- ungratefulness24
- unmannerliness23
- unpleasantness22
- unpreparedness24
- unreservedness22
- unskillfulness28
- unsociableness24
- untruthfulness25
- uproariousness20
- upstandingness24
- vegetativeness25
- verifiableness26
- victoriousness23
- villainousness23
- vindictiveness28
- vociferousness26
- voluminousness26
- voluptuousness26
- vulnerableness26
- waterproofness24
- watertightness22
- weightlessness23
- worshipfulness28
- worthwhileness26